Impact of Infratemporal Fossa Clearance on Survival in Advanced Buccal Mucosa Cancers.

Abstract

Buccal mucosa cancers are the most prevalent oral cavity cancers in South Asia, often attributed to widespread tobacco use. The current NCCN guidelines generally advise against primary surgery for locally very advanced (cT4b) buccal cancers involving the masticatory space and infratemporal fossa (ITF). However, some surgeons have adopted an aggressive surgical approach for T4b oral squamous cell carcinoma, involving composite resections and ITF clearance. This is a retrospective analytical survival study of 91 patients with very locally advanced buccal mucosa cancers with involvement of ITF (cT4b), who underwent radical surgery in the form of bi-alveolar composite resection with ITF clearance and Modified Neck Dissection from 2017 to 2023. At a median follow-up of 27 months, 54.9% of patients were alive and disease-free. The estimated mean 3-year overall survival (OS) and disease-free survival were 48% and 44%, respectively. In multivariate survival analysis, maxillary sinus involvement (p = 0.008), no response to neoadjuvant chemotherapy (p = 0.004), and nodal involvement (p = 0.05) were independent predictors of poor OS. Patients with high ITF involvement (n = 23) had a higher rate of distant metastasis compared to those with low ITF involvement (n = 68; p < 0.015). Presence of extra-nodal extension also significantly reduced survival across both groups (median OS: 10 months vs. 6.8 months; p = 0.037). ITF clearance is a safe and effective approach for managing locally very advanced (cT4b) buccal cancers.